The school – which has a roll of about 12,000 students from around the world, according to its website – is located about 150km west of Shanghai.
It offers courses in art, design, ceramics and fashion, among others.
In Yixing, police said emergency services were fully mobilised to treat the wounded and provide follow-up care for those affected by the attack.
‘Mental health’
No video of the attack was immediately seen on social media – a sign authorities possibly removed footage from various platforms.
Violent knife crime is not uncommon in China, where firearms are strictly controlled, but attacks with such a high death toll are relatively rare.
Earlier this week, a 62-year-old man killed 35 people and wounded more than 40 more when he rammed his small SUV into a crowd in the southern city of Zhuhai.
Web users said they were shocked by the week’s two deadly attacks.
“What kind of state of despair must these people be in to go to such extremes?” said one user of the popular X-like site Weibo.
“Security on campuses must be boosted, along with more education about mental health, so other dramas like these do not happen,” said another user.
“The rich-poor divide is getting bigger and bigger. Everyone must work hard these days to survive,” lamented another on Weibo.
It seemed certain comments were being taken down from Weibo, notably under posts with official media accounts of the Yixing incident.
CCTV’s message appeared to have sparked 6357 comments, but only a handful were visible.
Beyond the incidents in Yixing and Zhuhai, there has been a spate of other attacks in recent months.
In October, in Shanghai, a man killed three people and wounded 15 others in a knife attack at a supermarket.
And the month before, a Japanese schoolboy was fatally stabbed in the southern city of Shenzhen, which borders Hong Kong.
In March 2014, a knife attack on train passengers at a station in Kunming left about 30 people dead and more than 140 wounded.
Authorities blamed separatist militants from the troubled Xinjiang region for that incident.